The act of anal sex between two males, by the person standing firmly behind. While it can theoretically also refer to heterosexual anal sex, bumrush is exclusively used in practice to refer to anal sex between two men. More specifically the tops '''does''' the bumrushing, while the bottoms '''gets''' bumrushed.

1) (n) Crash the gates of a show with a pack of people, in the hope to get in without having to pay. "Yo! Bumrush the show" -- Public Enemy. (Yo! Bumrush the show) 1987.
2) (v) To get beaten up by a large, angry group of people. Literally to get rushed by bums or lowlifes.